Duration of psoriatic arthritis as a risk factor for myocardial infarction

OBJECTIVES: The aim was to examine the association between disease duration and risk of myocardial infarction (MI) in patients with PsA. METHODS: We used nationwide registry data from Denmark to estimate incidence rates per 1000 person-years and the risk of MI [adjusted hazard ratios (HRs) with 95% CIs] in rheumatologist-diagnosed patients with PsA using Cox regression models. The study period was between 1 January 2008 and 31 December 2012. RESULTS: The study population comprised a total of 8071 patients with PsA and 4 348 857 general population control subjects. A total of 156 and 54 215 MIs occurred during follow-up among patients with PsA and the reference population, respectively. There was a significant association between the duration of PsA and risk of MI (adjusted HR = 1.02; 95% CI: 1.01, 1.03 for each additional year after PsA diagnosis). Stratified based on short (<2 years) and long (≥2 years) disease duration, the adjusted HRs were 0.96 (95% CI: 0.60, 1.52; P = 0.8487) and 1.29 (95% CI: 1.09, 1.53; P = 0.0026), respectively. Other significant predictors included age, sex, socio-economic status, smoking, alcohol abuse, diabetes, hypertension and previous cardiovascular disease. CONCLUSIONS: We observed an increased risk of MI associated with longer duration of PsA. Our findings call for increased focus on disease duration in the cardiovascular risk assessment among patients with PsA.